Make things glow in the game engine
If the object is supposed to move around, you're best off parenting a point lamp to it of the same color. 


Add lamp and object at the same location
Make material for object "shadeless"
Make lamp same color (copy/paste hexadecimal values)
Parent lamp to object
Profit




if the object isn't going to be moving i.e. a stationary lamp or glowy gem, or wall torch or dropped phone the best route to take is to bake all the textures of the objects around it. this should save alot of processor speed since it doesn't have to render another lamp.

if you want me to write that part too, I can. but for now look up "cycles texture baking" on youtube. it will make your life much happier.